Transition metal compound, polymerization catalyst using same and process for producing styrenic polymer using said polymerization catalyst

Abstract

There are disclosed a transition metal compound of the general formula RMXa-1Lb (R is a pi ligand, a fused polycyclic cyclopentadienyl group in which at least one of many-membered rings to which cyclopentadienyl groups are fusedly bonded is a saturated ring, M is a transition metal, X is a sigma ligand, L is a Lewis base, a is the valency of M, and b is 0, 1 or 2); a polymerization catalyst for styrene, etc. comprising the above transition metal, preferably further comprising an oxygen atom containing compound ionic compound or organoboron compound and optionally a Lewis base; and a process for producing a polymer of a compound containing an ethylenically unsaturated double bond or an acetylenic polymer, especially a syndiotactic polystyrene by using the above polymerization catalyst. The catalyst is particularly effective for producing highly syndiotactic polystyrene minimized in residual metals amounts at a low cost in enhanced efficiency.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to a transition metal compound, a polymerization catalyst using the same and a process for producing a styrenic polymer using said catalyst. More particularly, it pertains to a transition metal compound which is useful as a component of a polymerization catalyst for a compound containing an ethylenically unsaturated double bond or acetylene series, especially of a polymerization catalyst for styrene series; a highly active polymerization catalysts which contains the above-mentioned transition metal compound and serves for a compound containing an ethylenically unsaturated double bond or acetylene series; and a process for efficiently producing at a low cost, a styrenic polymer which has a high degree of syndiotactic configuration and is minimized in the amounts of residual metals by the use of the aforesaid polymerization catalyst.2. Description of Related ArtsOlefinic polymers such as polyethylene and...

AI Technical Summary

Benefits of technology

It is a further object of the present invention to provide a process for efficiently producing at a low cost, a styrenic polymer which has a high degree of syndiotactic configuration and is minimized in the amounts of residual metals by the use of the aforesaid polymerization catalyst.

In order to achieve the above-mentioned objects, intensive research and investigation were continued by the present inventors. As a result, it has been found that a transition metal compound of a specific constitution having, as a .pi. ligand, a fused polycyclic cyclopentadienyl group in which at least one of many-membered rings to which cyclopentadienyl groups are fusedly bonded is a saturated ring is useful as a component of a polymerization catalyst for a compound containing an ethylenically unsaturated double bond or acetylene series; that a polymerization catalyst which comprises in combination, the above-mentioned transition metal, at least one from an oxygen atom containing compound, a specified ionic compound and an organoboron compound and optionally a Lewis acid possesses a high activity and thereby can efficiently polymerize a compound containing an ethylenically unsaturated double bond or acetylene series; and in particular that a styrenic polymer which has a high degree of syndiotactic configuration and is minimized in the amounts of residual metals is efficiently obtained at a low cost by polymerizing a styrenic polymer using the aforesaid polymerization catalyst. The present invention has been accomplished on the basis of the aforestated finding and information.

Problems solved by technology

However, sufficiently satisfactory catalytic-activity has not been obtained from a catalyst among them comprising a transition metal compound in which the .pi. ligand is a fused polycyclic cyclopentadienyl group containing an aromatic ring such as indenyl group or fluroenyl group.

However, such styrenic polymers having atactic configuration have disadvantage that it is inferior in heat resistance and chemical resistance.

However, the catalyst comprising the transition metal compound containing, as a .pi. ligand, a fused polycyclic cyclopentadienyl group having an aromatic ring such as an indenyl group suffers a disadvantage that the catalyst fails to attain a sufficient catalytic activity.